write-through cache datasets

just4u_sharath · Post by **just4u_sharath** » Mon May 07, 2012 4:17 pm

what does write-through cache dataset mean? I came across this in IBM book.

ray.wurlod · Post by **ray.wurlod** » Mon May 07, 2012 8:06 pm

Which book? What is the context? I did not find the term using a search against the Information Center

just4u_sharath · Post by **just4u_sharath** » Tue May 08, 2012 8:29 pm

Following is the link to the pdf
http://www.redbooks.ibm.com/redbooks/pdfs/sg247830.pdf
chapter2: topic 2.2.1

ray.wurlod · Post by **ray.wurlod** » Tue May 08, 2012 8:58 pm

OK, in that scenario "write-through cache" is similar to "staging area". The target Data Set is used as a holding area for data to be loaded into a table that is also being used as a source by the job, to avoid locking issues. Data Sets are ideal for this role because, unlike other mechanisms, they store data in exactly the same format as is used within DataStage - indeed, if you examine the score the operator used to read or write a Data Set is copy (the in-memory data set is simply copied to or from the on-disk structure).